Published patent application FR 2 256 687 describes a riveted assembly comprising a lightweight structure extending between two thin walls. The rivet possesses a frustoconical intermediate portion for coming into contact with the lightweight structure, and two cylindrical ends that are for coming into contact essentially with the thin walls. Each end is provided with an enlarged projecting abutment for holding the assembly made up of the lightweight structure and the two walls sandwiched together.
Nevertheless, the enlarged abutments of such a rivet are bulky in size and cannot be made smaller without compromising the mechanical characteristics of the rivet. There therefore exists a need for a novel type of riveted assembly.